Abstract 13442: Right Ventricular Outflow Tract Doppler Notching: A Sensitive Non-Invasive Discriminator of Pulmonary Vascular Disease in Patients With Heart Failure With Preserved Ejection Fraction

Abstract

Introduction: Pulmonary hypertension (PH) in the setting of heart failure with preserved ejection fraction (PH-HFpEF) is further characterized as isolated post-capillary PH (IpcPH) or combined pre- & post-capillary PH (CpcPH). This is distinguished by pulmonary vascular resistance (PVR) cut-off of 3 WU. Prior definitions used a diastolic pulmonary gradient (DPG) cut-off of 7mmHg to distinguish PH subtype. Studies have examined echocardiographic right ventricular outflow tract Doppler notching (RVOT-notch) as a correlate for pulmonary vascular disease, though its role in distinguishing PH-HFpEF subtype by current vs. prior definition has never been described. Hypothesis: Our study explores the ability of RVOT-notch to distinguish CpcPH from IpcPH in patients with PH-HFpEF, in the context of current PVR & prior DPG cutpoints. Methods: We retrospectively reviewed patients with PH-HFpEF referred to our PH program who underwent right heart catheterization and echo (later reviewed independently by blinded cardiologists to assess RVOT-notch). Results: 86 patients with PH-HFpEF were reviewed with a mean age of 66 and female predominance. Patients with RVOT-notch had signs of worsening right heart function both via echocardiography (higher estimated PASP, more severe TR, lower TAPSE) & hemodynamically (higher DPG, higher PVR, and lower pulmonary arterial compliance). RVOT-notch was able to distinguish CpcPH from IpcPH, with current PVR cut-off ≥3 WU (sensitivity 91%, specificity 68%, PPV 76%, NPV 88%) and prior DPG cut-off ≥7mmHg (sensitivity of 94%, specificity 58%, PPV 57%, NPV 94%). Conclusions: In PH-HFpEF, RVOT-notch is a sensitive marker of CpcPH, and notably better reflects the current PVR-based definition (PVR≥3) with better specificity than prior DPG-based definition. This could have implications as non-invasive screening for CpcPH in patients with PH-HFpEF. Further work is needed to validate this marker in larger cohorts.